不同细粒含量与间断比下不连续级配砂砾土渗蚀的CFD-DEM数值模拟

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中文摘要：基于CFD-DEM方法，开展了不同细粒含量(质量分数，下同)与间断比下不连续级配砂砾土渗蚀数值试验，从宏细观角度研究了细粒含量与间断比对渗蚀的联合作用机理。研究结果表明:土体侵蚀率随间断比的增大而增加，当间断比G较小(G<3)时，土样内部未发生颗粒迁移现象，表现出较好的内部稳定性，与KÉZDI判别准则吻合。当细粒含量不同时，间断比对渗蚀宏细观特征行为影响程度差异显著。当细粒含量较低(如15%)时，细颗粒较少参与土体内部应力传递，渗蚀过程中土样体积、强接触力链以及细颗粒应力分担系数几乎不发生改变，粗颗粒间孔隙直径增大，导致更多弱接触细颗粒流失，从而使得侵蚀率随间断比增加;相反，当细粒含量较高(如35%)时，参与应力传递的细颗粒比例相对较高，间断比增大导致粗颗粒数量减少，细颗粒流失易导致整个土体力链体系破坏，引起骨架颗粒重组变形，进而释放更多约束颗粒，加剧颗粒流失，故侵蚀率增加是孔隙直径增大和渗蚀过程中土骨架不断发生变形共同作用的结果。

外文标题：Numerical simulations of erosion of gap-graded sandy gravel soil with different fines contents and gap ratios using CFD-DEM

外文摘要：Based on the CFD-DEM method,numerical simulations in gap-graded sandy gravels with different fines contents(mass fraction,similarly hereinafter)and gap ratios(GR)were carried out to investigate the combined effects of fines content and gap ratio on suffusion from macro and micro perspectives.The results show that the erosion rate increases with increasing GR.No particle migration occurs within the soil samples when the GR is smaller than 3,demonstrating good internal stability.Furthermore,GR has a notable effect on suffusion behavior when the fines content(FC)varies.For instance,with a relatively low FC(e.g.,FC is 15%),fine particles play a limited role in stress transfer.During the erosion process,the sample volume,the strong contact force chain network,and the stress reduction coefficient remain relatively unchanged.This indicates that the increase in erosion rate is primarily attributed to the increased pore diameter among coarse particles and the loss of weak-contact fines.On the contrary,when the FC is relatively high(e.g.,FC is 35%),the fine particles actively participate in stress transfer,and an increase in GR can result in a reduction in the number of coarse particles.The loss of fine particles easily leads to the collapse of the entire force chain system,causing the skeleton particles to deform and rearrange,releasing more constrained particles and intensifying the loss of fine particles.Therefore,the main reason for the increasing erosion rate is the combined effect of the increasing pore diameter among coarse particles and the continuous deformation of the soil skeleton during suffusion.

外文关键词：

CFD-DEMsuffusiongap ratiogap-graded soilerosion ratioparticle migration

作者：

刘垒雷、邓刚、李维朝、陈锐、周超、徐立强

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作者单位：

哈尔滨工业大学(深圳)土木与环境工程学院,广东深圳,518055

广东省土木工程智能韧性结构重点实验室,广东深圳,518055

中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京,100038

香港理工大学土木与环境工程系,中国香港,999077

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关键词：

CFD-DEM 渗蚀间断比不连续级配土侵蚀率颗粒迁移

基金：

国家重点研发计划项目国家自然科学基金资助项目深圳市科技计划项目中国水利水电科学研究院基本科研业务费资助项目中国水利水电科学研究院基本科研业务费资助项目

项目编号：

2021YFC300100052278339KQTD20210811090112003GE0145B032021GE110145B0032023

出版年：

2024

DOI：

10.11817/j.issn.1672-7207.2024.07.020

中南大学学报(自然科学版)

中南大学

中南大学学报(自然科学版)

CSTPCD北大核心

影响因子：0.938

ISSN：1672-7207

年,卷(期)：2024.55(7)